The Mesoblast Ltd (ASX: MSB) share price is racing higher today.

Again.

Shares in the (as of now) S&P/ASX 300 Index (ASX: XKO) clinical-stage biotechnology company closed on Friday trading for $2.52. In earlier trade, shares were up 8.3% at $2.73 each. That saw the stock up an eye-popping 810% since this time last year.

Or enough to turn an $8,000 investment into $72,800. In just 12 months.

After some likely profit-taking, the Mesoblast share price is currently trading at $2.65, up 5.2%.

Here's what's grabbing ASX 200 investor interest today.

Mesoblast share price benefits from its own success

The ASX 200 biotech stock appears to be garnering additional tailwinds today generated by its own lengthy run higher.

You see, with the Mesoblast share price having roared from 30 cents a share 12 months ago to $2.65 today, the company's market cap has surged to $3.4 billion.

Why is that important?

Well, because this strong growth has helped earn Mesoblast a place in the ASX 200.

After market close on Friday, the company reported on S&P Dow Jones Indices' announcement that its shares will join the ASX 200 as of market open this Thursday, 6 March.

Mesoblast will replace ASX 200 lithium stock Arcadium Lithium (ASX: LTM), which is being acquired by mining giant Rio Tinto Ltd (ASX: RIO).

Earning a spot on the ASX 200 can help support the Mesoblast share price on numerous fronts.

First, ASX 200 shares tend to get more media attention and analyst coverage than smaller stocks, which could further increase Mesoblast's appeal to retail investors.

Second, the stock should benefit from upcoming buying from various index funds intended to track the performance of the ASX 200. Funds like the iShares Core S&P/ASX 200 ETF (ASX: IOZ) and the BetaShares Australia 200 ETF (ASX: A200) will now be adding Mesoblast shares to their holdings.

What's been happening with the soon-to-be ASX 200 biotech stock?

The Mesoblast share price was in the spotlight last Thursday, 27 February. That came as the company released its half-year results and a separate announcement on its core drug, remestemcel-L, or Ryoncil.

The earnings results were somewhat tepid. Revenue of US$3.2 million was down 6% year on year, while after tax losses were up 47% to US$47.9 million.

On the positive front, net cash outflow of US$20.7 million was down 22%.

As for Ryoncil – used to treat steroid-refractory acute graft-versus-host disease (SR-aGvHD) in children older than two years – Mesoblast CEO Silviu Itescu said, "Our FDA approved product Ryoncil will be available in the coming weeks to the children with SR-aGvHD in need of life-saving therapy."

And the Mesoblast share price got some added support with the company announcing it is working with the Blood and Marrow Transplant Clinical Trials Network in the United States to trial Ryoncil for adult patients with SR-aGvHD.